Measurements of the ground-state nuclear spins and magnetic and quadrupole moments of the copper isotopes from Cu61 up to Cu75 are reported. The experiments were performed at the CERN online isotope mass separator (ISOLDE) facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a Ni56 core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is, however, strongly reduced at N=40 due to the parity change between the pf and g orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the Ni56 core and weakening of the Z=28 and N=28 shell gaps.
ASJC Scopus subject areas
- Nuclear and High Energy Physics